Maxximus G-Force: First (and Last) Glimpse of a 1600-hp Beast

The invitation was brief, but intriguing. “Philanthropist and businessman David McMahan unveils the world’s newest, fastest, street legal supercar, officially certified by the World Records Academy. Please join us for breakfast and viewing this remarkable, beautifully crafted, one-of-a kind car, harnessing over 1600 horsepower.” Three eye-popping numbers that suggested that, if not the fastest, the G-Force might be one of the quickest cars in the world: 0–60 in 2.134 seconds; 0–100 in 4.541 seconds; 0–100–0 in 8.861 seconds.

We’re not sure if there is a real good way to harness 1600 hp, but if any car is going to be able to snatch “world’s fastest” status from the current titleholder, it’s going to need all the horsepower it can get. The record is currently held by, depending on who you ask, either the 1001-hp, 253-mph Bugatti Veyron 16.4 or the 1183-hp SSC Ultimate Aero (built by Shelby Supercars), the latter of which the Guinness Book of Records certified as the world’s fastest production car when it hit 256 mph in 2007. The 2009 Ultimate Aero now makes 1287 hp, for what it’s worth.

We arrived at the Peninsula Hotel in Beverly Hills, stood around the car’s satin-draped form, and waited, ready with questions. What is Maxximus? Where is it based? What exactly is under the hood of the G-Force? How much will it cost? How many will be built? And of course, when do we get to drive it? Within minutes, the regal Dr. McMahan wafted in, accompanied by Marion Kirby, the builder of the G-Force, to give us the answers.

The Ultimate Ultima

How does one build a car that beats the fastest cars in the world? Well, for an outfit as “mini” as Maxximus, starting with a solid basis was key. Kirby chose as his starting point Great Britain’s featherweight, mid-engine Ultima GTR720, which has been available as a kit or turnkey car in more or less the same form for a quarter of a century. The Ultima GTR is hardly new, but it’s always been quick. Our most recent GTR test happened way back in April 2000. An expensive car at $152,150 as tested, that example’s 345-hp Corvette-sourced LS1 V-8 powered the 2314-pound skateboard to a 3.3-second 0–60 time and an 8.2-second 0–100 time. It also pulled 0.98 g on the skidpad. Those are all impressive figures, even today. The later GTR720 uses a 720-hp small-block Chevrolet engine to generate acceleration figures that are among the best of all “production” street cars in history: 0–60 in 2.6 seconds, 100 mph in 5.3 seconds, and 0–100–0 in 9.4 seconds, according to Ultima.

Now, if starting with an existing car and then adding as much motor as necessary to beat records sounds easy, it isn’t (just ask Carroll Shelby how easy it was to turn the AC Ace into the 427 Cobra). Having worked on Ultimas before, Kirby knew he would need to add a lot more horsepower—his goal was 1500—and beef up much of the chassis to make even the smallest measurable gain over the GTR720. He chose a 434-cu-in aluminum Chevrolet V-8 and fitted it with huge, intercooled twin turbochargers; 16 fuel injectors; a five-stage oil pump; and more, resulting in “more than 1600 hp at the flywheel,” with 1500 lb-ft of torque, he says.

After several manual transaxles proved too brittle for the massive power, Kirby eventually settled on a paddle-shifted three-speed automatic. But fitting the new one-off engine/transaxle combo into the GTR’s engine bay required redesigning “a good portion of the tubular space-frame chassis,” a process that required hundreds of hours of custom fabrication.

Largely Stock Body, Airplane-Influenced Interior

It came together eventually, and the Ultima’s relatively unmodified blue-painted body panels, stock adjustable carbon-fiber wing, and 18-inch kit-spec wheels were installed. 245/35 front and 345/30 rear DOT-legal Hoosier A-6 tires provide the grip. The exhaust is now center-mounted, and the rear has been smoothed a bit, but otherwise, there is little to tell the G-Force from standard Ultimas. A pity, really—after all, what’s the point of having bragging rights to the world’s quickest car if it looks just like slower ones?

The G-Force’s cramped cabin is different, however, having been outfitted by an aircraft interior specialist, helping to somewhat mask this car’s kit-car origins. Still, it’s no Bentley. Think of a Lotus Elise cabin dolled out with a leather-covered dash and you’re close. Shoulder-to-shoulder seats are equipped with four-point harnesses. Ingress and egress over the foot-wide door sills, which contain lovely carbon-fiber-covered storage bins, is difficult.

But none of that mattered when, on October 7, 2008, Maxximus took the G-Force out to Rockingham Raceway in North Carolina. Kirby himself took the wheel and knocked off the aforementioned acceleration times, which if they’re not actual world records (there’s some question about whether the G-Force is a production car, or even a street-legal car), they’re quick enough to be. At this point, the car still has only 150 miles on it, so it’s really not even broken in.

Production Run of, uh, One

So . . . how much? When does production start? Well, it seems that when these guys say “one-of-a-kind,” they mean it. And as for that dream of owning the fastest car in the world? Well, dreams can be bought and sold, evidently. Although it was originally intended to be sold to McMahan, the G-Force is in the process of being sold to a foreign collector. So you can’t have it, and neither can we.

But that doesn’t mean they have stopped dreaming. Kirby said that he is indeed working on another project, one that we should see in 2011 or 2012. Presumably, it will be even quicker than this car. The none-too-modest McMahan stated, “I don’t think there’ll be anything that can beat the Maxximus, unless we build it.”

So with no way to buy the G-Force, no plans to make another one, and really, no opportunity for us to drive the thing and verify Maxximus’s extravagant claims, it seemed that this particular story wound up being little more than a car-guy fairy tale: a rich car-lover giving an affable, anonymous wrench-turner a blank check to build him a world-beater. We’re not sure if Kirby is the next Carroll Shelby, or if he is simply providing some rich dude 1600 new ways to kill himself.